UBUNTU-CVE-2024-35853
In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum_acl_tcam: Fix memory leak during rehash The rehash delayed work migrates filters from one region to another. This is done by iterating over all chunks (all the filters with the same priority) in the region and in each chunk iterating over all the filters. If the migration fails, the code tries to migrate the filters back to the old region. However, the rollback itself can also fail in which case another migration will be erroneously performed. Besides the fact that this ping pong is not a very good idea, it also creates a problem. Each virtual chunk references two chunks: The currently used one ('vchunk->chunk') and a backup ('vchunk->chunk2'). During migration the first holds the chunk we want to migrate filters to and the second holds the chunk we are migrating filters from. The code currently assumes - but does not verify - that the backup chunk does not exist (NULL) if the currently used chunk does not reference the target region. This assumption breaks when we are trying to rollback a rollback, resulting in the backup chunk being overwritten and leaked [1]. Fix by not rolling back a failed rollback and add a warning to avoid future cases. [1] WARNING: CPU: 5 PID: 1063 at lib/parman.c:291 parman_destroy+0x17/0x20 Modules linked in: CPU: 5 PID: 1063 Comm: kworker/5:11 Tainted: G W 6.9.0-rc2-custom-00784-gc6a05c468a0b #14 Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019 Workqueue: mlxsw_core mlxsw_sp_acl_tcam_vregion_rehash_work RIP: 0010:parman_destroy+0x17/0x20 [...] Call Trace: <TASK> mlxsw_sp_acl_atcam_region_fini+0x19/0x60 mlxsw_sp_acl_tcam_region_destroy+0x49/0xf0 mlxsw_sp_acl_tcam_vregion_rehash_work+0x1f1/0x470 process_one_work+0x151/0x370 worker_thread+0x2cb/0x3e0 kthread+0xd0/0x100 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1a/0x30 </TASK>
02 / AFFECTED SOFTWARE
Affected packages
10 explicit affected versions
27 explicit affected versions
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37 explicit affected versions
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10 explicit affected versions
31 explicit affected versions
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81 explicit affected versions
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10 explicit affected versions
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9 explicit affected versions
27 explicit affected versions
1 explicit affected versions
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51 explicit affected versions
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51 explicit affected versions
10 explicit affected versions
40 explicit affected versions
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51 explicit affected versions
7 explicit affected versions
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37 explicit affected versions
27 explicit affected versions
23 explicit affected versions
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1 explicit affected versions
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13 explicit affected versions
81 explicit affected versions
13 explicit affected versions
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7 explicit affected versions
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10 explicit affected versions
12 explicit affected versions
12 explicit affected versions
80 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
37 explicit affected versions
37 explicit affected versions
10 explicit affected versions
14 explicit affected versions
38 explicit affected versions
40 explicit affected versions
9 explicit affected versions
40 explicit affected versions
11 explicit affected versions
2 explicit affected versions
48 explicit affected versions
7 explicit affected versions
8 explicit affected versions
21 explicit affected versions
52 explicit affected versions
4 explicit affected versions
1 explicit affected versions
1 explicit affected versions
46 explicit affected versions
13 explicit affected versions
43 explicit affected versions
46 explicit affected versions
10 explicit affected versions
14 explicit affected versions
81 explicit affected versions
4 explicit affected versions
70 explicit affected versions
11 explicit affected versions
1 explicit affected versions
3 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum_acl_tcam: Fix memory leak during rehash The rehash delayed work migrates filters from one region to another. This is done by iterating over all chunks (all the filters with the same priority) in the region and in each chunk iterating over all the filters. If the migration fails, the code tries to migrate the filters back to the old region. However, the rollback itself can also fail in which case another migration will be erroneously performed. Besides the fact that this ping pong is not a very good idea, it also creates a problem. Each virtual chunk references two chunks: The currently used one ('vchunk->chunk') and a backup ('vchunk->chunk2'). During migration the first holds the chunk we want to migrate filters to and the second holds the chunk we are migrating filters from. The code currently assumes - but does not verify - that the backup chunk does not exist (NULL) if the currently used chunk does not reference the target region. This assumption breaks when we are trying to rollback a rollback, resulting in the backup chunk being overwritten and leaked [1]. Fix by not rolling back a failed rollback and add a warning to avoid future cases. [1] WARNING: CPU: 5 PID: 1063 at lib/parman.c:291 parman_destroy+0x17/0x20 Modules linked in: CPU: 5 PID: 1063 Comm: kworker/5:11 Tainted: G W 6.9.0-rc2-custom-00784-gc6a05c468a0b #14 Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019 Workqueue: mlxsw_core mlxsw_sp_acl_tcam_vregion_rehash_work RIP: 0010:parman_destroy+0x17/0x20 [...] Call Trace: <TASK> mlxsw_sp_acl_atcam_region_fini+0x19/0x60 mlxsw_sp_acl_tcam_region_destroy+0x49/0xf0 mlxsw_sp_acl_tcam_vregion_rehash_work+0x1f1/0x470 process_one_work+0x151/0x370 worker_thread+0x2cb/0x3e0 kthread+0xd0/0x100 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1a/0x30 </TASK>
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/8ca3f7a7b61393804c46f170743c3b839df13977
- https://git.kernel.org/stable/c/0ae8ff7b6d42e33943af462910bdcfa2ec0cb8cf
- https://git.kernel.org/stable/c/413a01886c3958d4b8aac23a3bff3d430b92093e
- https://git.kernel.org/stable/c/617e98ba4c50f4547c9eb0946b1cfc26937d70d1
- https://git.kernel.org/stable/c/8ca3f7a7b61393804c46f170743c3b839df13977
- https://git.kernel.org/stable/c/b3fd51f684a0711504f82de510da109ae639722d
- https://git.kernel.org/stable/c/b822644fd90992ee362c5e0c8d2556efc8856c76
- https://git.kernel.org/stable/c/c6f3fa7f5a748bf6e5c4eb742686d6952f854e76
- https://ubuntu.com/security/CVE-2024-35853
- https://ubuntu.com/security/notices/USN-6896-1
- https://ubuntu.com/security/notices/USN-6896-2
- https://ubuntu.com/security/notices/USN-6896-3
- https://ubuntu.com/security/notices/USN-6896-4
- https://ubuntu.com/security/notices/USN-6896-5
- https://ubuntu.com/security/notices/USN-6898-1
- https://ubuntu.com/security/notices/USN-6898-2
- https://ubuntu.com/security/notices/USN-6898-3
- https://ubuntu.com/security/notices/USN-6898-4
- https://ubuntu.com/security/notices/USN-6917-1
- https://ubuntu.com/security/notices/USN-6919-1
- https://ubuntu.com/security/notices/USN-6927-1
- https://ubuntu.com/security/notices/USN-6949-1
- https://ubuntu.com/security/notices/USN-6949-2
- https://ubuntu.com/security/notices/USN-6952-1
- https://ubuntu.com/security/notices/USN-6952-2
- https://ubuntu.com/security/notices/USN-6955-1
- https://ubuntu.com/security/notices/USN-7019-1
- https://www.cve.org/CVERecord?id=CVE-2024-35853